The proposed research is concerned generally with how motivation (food deprivation) affects learning, memory and performance. The accepted view today is that increasing deprivation increases the value of goal events but does not affect the associations formed (with the exception of associations to deprivation stimuli). Yet our research has shown that the value of consumption is not a simple increasing function of deprivation, and also that the value of goal events appears to enter into associations, rather than only determining current performance. In explanation of our previous findings, we propose here that the value of some consumable substances may increase with increasing hunger (calories?) while the value of others may decrease with decreasing hunger (sweetness?). This could be why desserts are eaten at the end of a meal. A series of experiments is proposed to determine how the value of consumption varies as a joint function of internal factors (degree of food deprivation) and external factors) type of food as well as other external factors). We hypothesize that as deprivation increases, the primary reinforcement associated with feeding is postingestive hunger reduction, with taste being less important, while at lower deprivation levels, taste variety and other cues producing feeding are more important than at higher deprivation levels. This reconciles some otherwise contradictory data. We also suggest that these different sources of reinforcement differ in their effects on instrumental performance and may differ generally in how they enter into associations.